It sound suspiciously like "halt still" in an east German accent.
if this is correct then it is translated 'keep still" or "don't move"
Confirmed by the link below !!
Halt can mean either check or break which are homophones of cheque and brake respectively.
Translation: Halt / Stop
stop suddenly/quickly
Halt!
it means to stop in the presence of a guard or a soldier when they tell you to
To disparage an activity or idea. Bring it to an abrupt halt.
The plural form of halt is halts.
Halt chose Will as his apprentice.
The word halt has one syllable.
Other words for stop are freeze, alto, veto, pause, quit
Halt originated from Hiberia but escaped when he was young.
Halt translates to JOOJIN, ISTAAJIN.